1. Field of the Invention
The present invention relates to a cooling system for removing excess process heat and/or machine heat from a paper or cardboard machine.
2. Discussion of Background Information
A device similar in general to the one discussed above is known from International Publication No. WO 97/44523, in which a cooling system of a paper mill uses a cooling tower to reduce the use of cooling water. The cooling tower, in addition to the fresh water flowing through it, takes over a substantial share of the heat removal in the paper mill.
However, one problem of the above-noted device is that, when using such cooling systems in a paper machine, the coolant liquids provided for the cooling function in the machine are usually oily, oil-containing, or other liquids with a high boiling point which may, to an extent, also serve lubrication purposes or are at least intended to protect against corrosion. Generally, these coolant liquids can be harmful to the environment and can also be detrimental to the paper manufacturing process if they reach the process cycle of the paper machine.